Arthroscopes and other similar optical instruments, such as endoscopes, are used in medical applications, such as surgery and examination, as well as in non-medical applications. Although embodiments of the present invention are described in the present application in the context of surgical arthroscopes, embodiments of the present invention may be useful for other applications and the present invention is intended to embrace all suitable variations.
Over the last fifteen or more years, the nature of surgery has changed substantially, with minimally invasive surgery becoming a standard of care. Within the orthopedic field, in particular, arthroscopy and similar techniques have become the most common surgical procedures. Surgery using such techniques is less painful for the patient and, in most instances, can be performed more quickly and safely than with techniques that require greater invasion of the patient's body. Furthermore, the anesthesia associated with arthroscopy and similar procedures is less complicated, more cost effective and can be handled on an outpatient basis. Patients return to normal life more quickly, and hospital stays may be reduced in length or even eliminated. However, all of these benefits are available only if minimally invasive surgery allows for better diagnostic capabilities, improved surgical techniques, and reduced iatrogenic damage.
One drawback of these minimally invasive techniques derives from the technical limitations of the arthroscopes, endoscopes and other principal optical instruments employed. In particular, one significant limitation is the limited field of view afforded by even the best commercially available instruments; in some respects these instruments and techniques have not changed significantly since the 1980s. Improvements in the field of view provided by an arthroscope or like instrument can improve the utility of such devices.
Several techniques for widening the view offered by arthroscopic/endoscopic instruments have been proposed. Generally, such proposals have entailed the packing of a plurality of movable lenses or prisms into the input end of the instrument, posing numerous design challenges and often resulting in various problems, such as precision of construction, precision of relative movements, space requirements, optical distortions, and elimination of undesired “ambient” light.
There is a need for an improved arthroscope that affords the user a broadened effective field of view and that does not require movement of the entire arthroscope to vary its scope of view. There is also a need for an arthroscope with an improved design for object capture and relay. In this specification and in the appended claims, the term “arthroscope” means and should be interpreted to include an endoscope or any other like optical instrument, whether used for surgery or otherwise.